21273416 has 8 divisors (see below), whose sum is σ = 39887670. Its totient is φ = 10636704.

The previous prime is 21273391. The next prime is 21273431. The reversal of 21273416 is 61437212.

It can be written as a sum of positive squares in only one way, i.e., 21252100 + 21316 = 4610^2 + 146^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1329581 + ... + 1329596.

Almost surely, 2^21273416 is an apocalyptic number.

It is an amenable number.

21273416 is a deficient number, since it is larger than the sum of its proper divisors (18614254).

21273416 is a wasteful number, since it uses less digits than its factorization.

21273416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2659183 (or 2659179 counting only the distinct ones).

The product of its digits is 2016, while the sum is 26.

The square root of 21273416 is about 4612.3113511557. The cubic root of 21273416 is about 277.0846140304.

The spelling of 21273416 in words is "twenty-one million, two hundred seventy-three thousand, four hundred sixteen".